The Centers for Disease Control and Prevention Receives Information About

Multiple Choice

The Centers for Disease Control and Prevention receives information about the causes for HIV/AIDS infection in the United States. Here are the causes of infection and their respective probability among American women age 20 to 24 years:
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$\begin{array}{c}\begin{array}{lll}\bf{Cause}\\\text{Injection drug use} \\\text{Heterosexual sex} \\\text{Perinatal infection} \\\text{Other causes}\end{array}\begin{array}{lll}\bf{Probability}\\? \\0.664 \\0.125 \\0.095\end{array}\end{array}$ What is the probability that an American woman age 20 to 24 contracted HIV/AIDS either via heterosexual sex or via perinatal infection?

A) 0.083
B) 0.211
C) 0.500
D) 0.789